Process for treating petroleum hydrocarbons



May 17, 1932. R. CROSS 1,859,027

PROCESS FOR TREATING PETROLEUM HYDROCARBONS Filed NOV. 4, 1927 (alzdeizser Efymer- IN VEN TOR BY Roy Cross JZM C5? A ITORNIEY ROY GROSS, OF KANSAS CITY,

Patented May 17, 1932 UNITED STATES PATENT OFFICE TION, OF WILMINGTON,

DELAWARE PROCESS FORgTRMTING PETROLEUM HYDROOARBONS Application filed November 4, 1927. Serial No. 231,110.

improvements in hydrocar- This invention relates to a process for treating petroleum bons, and refers method of treating hydrocarbon vapors with metallic sodium by intermixing the vapors with the sodium and subsequently after treatment separating the treating material from the treated hydrocarbon.

The application is a continuation in part and modification of previous application Serial No. 142,016, filed October 16, 1926.

The singlefigure is a diagrammatic side elevational view of an apparatus in which the process may be practiced.

The embodiment shown in the drawing discloses the treating system connected to a Cross cracking apparatus, but it will be understood that the treating system may be as well utilized on any type of cracking system or distillation apparatus.

Referring to the drawing, at 1 is shown a furnace divided by a bridge wall 2, into a combustion chamber 3 and a tube chamber 4. In the tube chamber is a pipe coil 5, in which the cracking stock is heated. The tube bank 5 is connected by a transfer line 6 to a heavily insulated forged steel reaction chamber 7, which has removable end plates to facilitate cleaning. The discharge line 8 from the reaction chamber is connected into the evaporator 9. A pressure reduction valve is interposed in the transfer line 8. The evaporator 9 is equipped with an overhead vapor line 10 communicating with the bubble tower 11 and a bottom liquid draw-off line 12, con

trolled by a valve 13 manipulated through an automatic liquid level regulating device 14. The discharge pipe 12 terminates in a cooling coil 15, positioned in the cooling box 16. The bubble tower 11 has a two-way vapor line, one of which pipes is designated as 17 and connects with the line 18, which terminates in the condenser coil 19 positioned in the condenser box 20. The other vapor line 21 connected into the top trolled by a valve 22 and connects with a pipe 23 which terminates in a separator 24.

A molten sodium reservoir or tank 25 has a connection 26 controlled by a valve 27 also connected into the line 23.

more particularly to a of the tower is con The separator 24 has an overhead vapor line 18 and a bottom liquid draw-off line 28, regulated by a valve 29. i

The condenser coil 19 terminates in a line 30, which communicates with a gas separator 31 which has a valve controlled'gas relief line 32 and a valve controlled liquid draw-oft" line 33.

The operation of. the Cross cracking system may be briefly described as the functioning of the cracking end of the system and forms no part of the novelty in the present invention.

Oil is introduced from any convenient storage through the pipe 34 and is charged by means of the pump 35 through a line 36, a portion of which consists of a coil 36, positioned in'the top of the bubble tower to assist in dephlegmation of the vapors. The continuation of the line 36 directs the preheated oil to the pipe 37 by means of which the oil is directed to the heating coil' 5 in the furnace 1.

In the furnace the oil is raised to a cracking temperature and the velocity and duration of heating so regulated that there is no objectionable accumulation of free carbonaceous matter in the coil 5. 7

At the cracking temperature the oil is directed through the transfer line 6 and collected in a considerable body in the reaction chamber 7, where suflicient time is permitted to consummate the reaction instituted in the heating coil. Asv suggested the reaction chamber is heavily insulated to prevent loss of heat by radiation. Also all lines and connections through the cracking system are insulated to prevent similar losses. After the reaction period has expired the oilis discharged through the pipe 8 and the pressure is reduced at the valve 10. Normally in operation on common types of charging stock temperatures from 700 to 1,000 F. and pres sures from 500 to 1500 pounds per square inch are utilized.

With the reduction of pressure the oil introduced to the evaporator flashes the lighter portions passing overhead in the form of vapors through the line 10 to the dephlegmating tower 11, while the unvaporlzed prodnote are drawn off through the pipe 12 and after cooling are directed through the pipe 38 to storage.

The overhead material introduced into the bubble tower rises upwardly against the gravitating liquid condensate separatedout in the tower, whereby the lighter fractions are refluxed. The still vaporized material passes oil from the top of the bubble tower to the line 21, and is introduced to the pipe 23 at a point where molten sodium is injected thereto and intimately combined therewith. The molten sodium is contained in the vessel 25 and is maintained in a molten condition by means of a steam heating coil 39, or other suitable means for heat. The container is heavily insulated as are the connecting lines throughout the system.

In order to inject the molten sodium into the oil vapors, gases and vapors are taken off from the top of the reaction chamber through the pipe 40 regulated by a valve 41. These gaseous vapors pass up through the line 42 and pipe 43 controlled by valves 44 and 45 respectively.

At a position designated as 46 is an injector through which the high pressure gases pass, drawing with them the molten sodium supplied from the tank 25 through the line 26. This mixture of vapor, gas and sodium thoroughly intermingled and broken up into minute supplied to the pipe 23 through the line 21.

he mixture passes to the baflie separator 24 i where the vapors are separated from the liquid treating substance. The molten sodium contaminated with a certain amount of liquid distillate is drawn ofi' through the line 28, where it is purified to recover the sodium or reuse. The treated vapors pass over through-the line 18 into the condenser coil 19 and are collected as liquid distillate in the gas separator 31. In the event that it is not feasible to take the high pressure gases and vapors from the reaction chamber, extraneous gases may be introduced through the pipe 47 controlled by a valve 48. For cleaning the apparatus steam may be injected through pipe 47. Furthermore the treating system may be cut out of the cracking system by closmg the valve 22 and the valve 48 in the line 18 and opening the valve 49 in the line 17 whereby the treating system is directed without treatment to the condenser.

In the event that there is any accumulation of distillate in the line 42, it may be drained back into the evaporator through the pipe 51 or diverted from the system through the line 52. Valves are positioned in the respective lines 50, 51, and 52 for controlling this operation, also there may be a collector tank interposed in the line in which distillate may be collected prior to its return to the evaporator, or prior to its being withdrawn through the type of gas or vapor eague? The condensate collected in the bottom of the bubble tower is withdrawn through the pipe 53 regulated by a valve 54, which valve is manipulated by an automatic liquid level regulating device 55. This condensate accumulates in thetank 56 from which it is withdrawn and recharged to the line 37 by means of a pump 57 The method herein described has to do with the injection of metallic sodium in the form of sodium mist into a stream of hydrocarbon vapors to be treated. As suggested, the specific illustration shown in the drawing, the hydrocarbon vapor is gasoline made by high temperature cracking of relatively heavy hydrocarbons. However, the present invention is not limited to the treatment of this product as it obviously may be supplied to any other hydrocarbons in the vapor state or partially in the vapor state, such as heavier distillates of the type of kerosene or even lubricating oil distillates, at normal pressures or at reduced pressures.

In the treatment of lubricating oils in the vapor state the injection would be at reduced pressures of what is commonly termed end vacuum conditions.

Among the important advantages of the present invention is the use of an injecting medium in the form of vapor or gas which is my m ecting medium which will not react with metallic sodium is contemplated whether it be hydrocarbon vapor or gas, or any other injected from an .extraneous source.

In the treatment of the vapors of cracked gasoline during the process of their manufacture, it would normally be the vapors or gases of the system which would be used as an injecting medium. In the specific embodiment given herewith in the application of this process to the Cross cracking process the vapors and gases from the reaction chamber would be used. These vapors and gases are present in the reaction chamber under pressures of from 500 to 2000 pounds per square inch, and their chemical composition is ideal as an injecting material for the sodium, not only by reason of their chemical composition and high pressures, but because of their physical properties which produce a finely divided mist of the metallic sodium and tend to keep 'the mist or vapor in discrete or finely divided form.- The combination of sodium and hydrocarbon vapor directed to the separator might be called a liquid sodium hydrocarbon vapor emulsion with the liquid sodium in the internal phase. The globules of sodium are so small as to be highly reactive throughout their entire diameter.

' In some instances it is of course necessary to control the degree. This actual temperature will vary with the different types of oil. The actual relatively inert in the presence of sodium.- particles 15 combined with the vapor A temperature to the optimum temperatures employed will be controlled as shown in the apparatus herewith, not only for the purpose of getting the optimum results in treatment in the way of sulphur removal or bleaching, but also to obtain the right degree of fractionation or end point temperature of the product.

A wide variation in both temperature of treating and end point maybe had by reason of the ability to change the temperature of the vapor at will, as well as the pressure. The higher the pressure of course the higher is the temperature at which a product of a given end point may be treated.

The requirement for heating the sodium and keeping the lines well insulated is necessitated by the fact that the sodium will solidify or freeze at temperatures of substantially 96 0.

. The valve 27 regulates the dosage of sodium and in place of th valve a pump of small capacity may preferably. be used. Such a pump would be of necessity constructed of iron having small piston displacements.

The high pressure injecting gases and molten metallic sodium mix in the injector 46, forming a mist in the line 23. The speed or velocity of the vapors is diminished in the separator 24 which contains baflie plates to clean out any sodium sludge and higher boiling point hydrocarbon fractions.

- The treatment obviously can apply in the same manner to gasoline, kerosene or heavy distillates directly obtained from crude oil or from the rerun of once run petroleum of any type. Furthermore the hydrocarbon to be treated, particularly in the case of gasoline, can not only bev material to be treated but the injecting medium, in such cases a separator alone is required.

I claim as my invention:

1. A method of treating 7 etroleum hydrocarbons substantially in the vapor phase, which consists in injecting metallic sodium in the form of a mist into a stream of said hydrocarbons and utilizing an inert hydrocarbon gaseous vapor at pressures substantially in excess of the vapor pressure of the hydrocarbon to accomplish the intimate combination of the sodium and separating the suspended liquid and solids from the treated vapors and condensing the vapors.

2. A method of treating petroleum hydrocarbons substantially in the vapor phase,

which consists in continuously injecting netallic sodium in the form of a mist into a stream of such vapors discharged from a cracking system and subsequent to fractionation, utilizing the non-reactive gaseous vapors from the system to produce the sodium injection and combination of the sodium and vapors and separating the suspended liquid and solids from the treated vapors and condensing the vapors.

3. A method of treating hydrocarbons in the vapor phase comprising the steps of atomizing liquid metallic sodium by introducing a stream of the metal into a stream of inert high pressure hydrocarbon vapor in an injector, subsequently intermingling the hydrocarbon vapors to be treated with the atomized sodium, and separating the sodium from the hydrocarbon.

4. A method of treating hydrocarbon vapors comprising the steps of combining with liquid sodium a non-reactive hydrocarbon gas, intermingling the mixture with the hydrocarbon vapors, said metal and gasbeing maintained at pressures substantially in excess of the pressures of the hydrocarbon vapors, and separating the metal and polymers from the hydrocarbon material.

ROY CROSS. 

